[ns] About AODV RREP lost due to Collision at MAC layer

[nadir shah]

Dear All,
 I am implementing a protocol based on AODV but i am disabling 
certain functions like hello and other function. I am facing a problem, that is 
when I send the RREP, often the RREP is lost due to collision at MAC layer, 
mostly RTS packets. it has a great impact on my simulation.

My question is that how to handle this issue? How it  is handled in normally 
standard protocol?

Waiting for your reply..


With Best Regard,

Nadir Shah



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[ns] about AODV

[胡杰]

 
hi, 
 

I want to record the node's neibor count:

 

my try：

step 1: add a variable in aodv.h，used to record the numbers of neighbors,i 
modify the code as follows:

aodv_rtable rthead; // routing table

aodv_ncache nbhead; // Neighbor Cache

aodv_bcache  bihead; // Broadcast ID Cache

//***add for NCR

 int nbcount;

//** 

step 2:  modify the struct "hdr_aodv_request" in file  "aodv_packet.h":as 
follows

//   u_int8_treserved[2];

  u_int8_t   NCR;

  u_int8_t   reserved;

 

step 3:modify "void AODV::recvHello(Packet *p)" in file "aodv.cc":as follows

void AODV::recvHello(Packet *p) {

   //struct hdr_ip *ih = HDR_IP(p);

struct hdr_aodv_reply *rp = HDR_AODV_REPLY(p);

AODV_Neighbor *nb;

nb = nb_lookup(rp->rp_dst);

if(nb == 0) {

   nb_insert(rp->rp_dst);

   //**add for NCR

 nbcount++;

   //**

 }

else {

   nb->nb_expire = CURRENT_TIME +(1.5 * ALLOWED_HELLO_LOSS * 
HELLO_INTERVAL);

 }

 Packet::free(p);

}

 

modify  "void AODV::nb_purge()" as follows:

AODV::nb_purge() {

AODV_Neighbor *nb = nbhead.lh_first;

AODV_Neighbor *nbn;

double now = CURRENT_TIME;

for(; nb; nb = nbn) {

   nbn = nb->nb_link.le_next;

   if(nb->nb_expire <= now) {

 nb_delete(nb->nb_addr);

 //*add for NCR*

 nbcount--;

 //*

   }

}

 modify the "void AODV::sendRequest(nsaddr_t dst)" in file "cmu_trace.cc"as 
follows:

 sprintf(pt_->buffer() + offset,

 "[0x%x %d %d [%d %d] [%d %d]] %d (REQUEST3)",

 rq->rq_type,

rq->rq_hop_count,

rq->rq_bcast_id,

rq->rq_dst,

rq->rq_dst_seqno,

rq->rq_src,

rq->rq_src_seqno,

//

rq->NCR);

//*

²the result: 

s 10.0 _0_ AGT  --- 0 tcp 40 [0 0 0 0] --- [0:0 8:0 32 0] [0 0] 0 0

r 10.0 _0_ RTR  --- 0 tcp 40 [0 0 0 0] --- [0:0 8:0 32 0] [0 0] 0 0

s 10.0 _0_ RTR  --- 0 AODV 48 [0 0 0 0] --- [0:255 -1:255 30 0] 
[0x2 1 1 [8 0] [0 8]] 2 (REQUEST3)

r 10.001340360 _1_ RTR  --- 0 AODV 48 [0  0 800] --- [0:255 -1:255 
30 0] [0x2 1 1 [8 0] [0 8]] 2(REQUEST3)

r 10.001340810 _2_ RTR  --- 0 AODV 48 [0  0 800] --- [0:255 -1:255 
30 0] [0x2 1 1 [8 0] [0 8]] 2(REQUEST3)

s 10.006801271 _2_ RTR  --- 0 AODV 48 [0  0 800] --- [2:255 -1:255 
29 0] [0x2 2 1 [8 0] [0 8]] 2 (REQUEST3)

r 10.008081677 _3_ RTR  --- 0 AODV 48 [0  2 800] --- [2:255 -1:255 
29 0] [0x2 2 1 [8 0] [0 8]] 2 (REQUEST3)

r 10.008081837 _1_ RTR  --- 0 AODV 48 [0  2 800] --- [2:255 -1:255 
29 0] [0x2 2 1 [8 0] [0 8]] 2 (REQUEST3)

r 10.008081986 _4_ RTR  --- 0 AODV 48 [0  2 800] --- [2:255 -1:255 
29 0] [0x2 2 1 [8 0] [0 8]] 2 (REQUEST3)

r 10.008082081 _0_ RTR  --- 0 AODV 48 [0  2 800] --- [2:255 -1:255 
29 0] [0x2 2 1 [8 0] [0 8]] 2 (REQUEST3)

… …

 

Re: [ns] about AODV

[Mubashir Rehmani]

Hi,

To broadcast Hello messages periodically, you should comment the following
two lines in aodv.cc

00092 #ifndef AODV_LINK_LAYER_DETECTION


00095 #endif // LINK LAYER DETECTION

and then do make
make clean
sudo make install

and you will see hello packets in your trace file.

Feel free to contact me

Regards

Mubashir Husain Rehmani

2008/10/28 胡杰 <[EMAIL PROTECTED]>

>
>
>
>
>
>  hello:
>
> in aodv protocol, nodes periodically broadcast HELLO messages, i want
> to use this mechanism to caculate the node's neighbor change ration. How can
> i do this.
>
> thank you very much.
>



-- 
Mubashir Husain Rehmani

Mobile :   00 33 (0)6 32 00 89 35

[ns] about AODV

[胡杰]

 
 
 
 hello:
 
 in aodv protocol, nodes periodically broadcast HELLO messages, i want to 
use this mechanism to caculate the node's neighbor change ration. How can i do 
this. 
 
 thank you very much.

[ns] about AODV protocol in reall life

[adi suryo wibowo]

I was simulated aodv and now I have question what example
implementation about AODV protocol in real life?
this is just teory or are there usefull implementation about  MANET in
our daily life?
as i know MANET just support Share file or data, can you told me about
other implementation in recent time?



thanks for your attention
Regards
stt Telkom student